#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <fcntl.h>

void error_handling(char *string);

int main() {

    int serv_sock, clnt_sock;

    struct sockaddr_in serv_addr;
    struct sockaddr_in clnt_addr;
    socklen_t clnt_addr_size;

    char *message = "hello,world!";

    if ((serv_sock = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
        error_handling("socket() error");
    }
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(8080);

    if (bind(serv_sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) == -1) {
        error_handling("bind() error");
    }

    if (listen(serv_sock, 5) == -1) {
        error_handling("listen() error");
    }

    clnt_addr_size = sizeof(clnt_addr);

    if ((clnt_sock = accept(serv_sock, (struct sockaddr *) &clnt_addr, &clnt_addr_size)) == -1) {
        error_handling("accept() error");
    }

    write(clnt_sock, message, strlen(message));
    close(clnt_sock);
    close(serv_sock);
    return 0;
}

void error_handling(char *string) {
    fputs(string, stderr);
    fputc('\n', stderr);
    exit(1);
}
